Process of disintegrating and comminuting minerals or ores.



Ilrvrrnn TATES Parent firme EDIVARD LESLIE GRAHAM, OF UPPER IVARLINGHAM, ENGLAND.

PROCESS OF DlSINTEGRATING AND COMMINUTING MINERALS OR ORES.

EEEGIFICATION forming part of Letters Patent No. 689,959, dated December 31, 1901.

Application filed March 26,1901. Serial No. 52,959. (No specimens To all whom it may concern.-

Be it known that I, EDWARD LESLIE GRA- HAM, a citizen of Great Britain, residing at Upper IVarlingham, in the county of Surrey, England, have invented a new and Improved Process for the Disintegration and Comminution of Minerals or Ores, of which the following is a specification.

This invention relates to a process for the disintegration and comminution of minerals or ores without the necessity of mechanical crushing thereof in stamp-mills or crushinginills, as is usually required before the extraction or winning of the metal from the ore.

The invention is applicable to the treatment of ores containing metals in their native state or combined, for example, as oXids, sulfids, carbonates, haloid salts, arsenides,or antimonides; and the invention has for its object to disintegrate minerals or ores to such a condition that the gangue may be conveniently separated by any known and convenient mechanical means of concentration.

The invention generally consists in the treatment of ores within a bath containinga solution of an acid within which it is subjected to the action of an electric current.

In general it is preferred to employ a solution of sulfuric acid or of hydrofluoric acid, or of both sulfuric and hydrofluoric acids, for the purpose; but other acids may be employed and barium chlorid, ammonium chlorid, or ammonium carbonate may be added. The process may be also rendered more eifective by the addition in certain cases of a quantity of fluor-spar.

In carrying the invention into effect a vat of any suitable non-conducting material is provided and electrodes introduced therein or mounted on the sides thereof, which are connected to a dynamo or other source of electric current. It is preferred to arrange a number of such vats in series, the respective electrodes being connected together in the electric circuit. Suitable channels may be provided beneath each of the vats by which the disintegrated and comminuted ore may be conducted to any suitable sizing or concentrating apparatus.

In the treatment of free-milling gold ores according to the invention it has been found that a solution of two and a half per cent. of

sulfuric acid and one per cent. of hydrofluoric acid gives excellent results. In the treatment of refractory gold ores according to the invention a solution of five per cent. of sulfuric acid has been found to answer Well, While in other cases a solution of from two to five per cent. of sulfuric acid with one to one and a half per cent. of hydrofluoric acid has given good results.

In the treatment of some copper ores asolution of two and a half per cent. of sulfuric acid is effective, while in the treatment of other copper ores and of a silver, gold, and antimony ore it has been found that a solution of three per cent. of sulfuric acid with one and a half per cent. of hydrofluoric acid is effective.

In almost all cases of ores containing gold, silver, and copper a solution of sulfuric acid from two to five per cent., either alone or in combination with a solution of hydrofluoric acid of from one to one and a half per cent. or of hydrofluoric acid alone will have the effect of disintegrating and comminuting the ore, so as to render the sizing and concentration to be effected without the necessity of mechanical crushing.

The invention is not confined to the acids specifically prescribed.

The electric current may have an electromotive force of fifty volts for the treatment of the ore in one vat; but the current would be increased according to the number of vats employed, as well as according to the description of ore treated.

It has been found that the addition of fluor spar in the proportion of about one-fifth of the bulk of ore to be treated accelerates the -disintegration and renders the process more effective.

It has been found that the process is of general application to all metalliferous ores.

The ore after treatment in the process according to the invention can be subjected to any convenient ordinary treatment by means of which the metal carried by it may be extracted.

The action of the current on the solution has the effect of generating gases which disintegrate the ore.

What I claim as my invention, and desire to secure by Letters Patent, is-- Ice 1. The process for treating ores consisting in the following steps; first immersing the ore Without preliminary heating in acold acid solution incapable of dissolving it; secondly passing an electric current of sufficient Without preliminary heating in a solution ofsulfuric acid to which finer-spar has been added and which isincapable of dissolving the ore, secondly sending an electric current of sufficient strength to disintegrate the ore through the solution and finally extracting the ore substantially as set forth. 7

4. The process of treating ores, consisting ofthe following steps; first immersing the ores in a solution of sulfuric and hydrofluoric acids incapable of dissolving the ore; secondly passing an electric current of sufficient strength to disintegrate the ore through the solution and thirdly extracting the metal from the ore all substantially as set forth.

In testimony whereof I have signed my' name to this specification in the presence of a two subscribing Witnesses.

EDWARD LESLIE GRAHAM. Witnesses:

WILLIAM EDWARD EVANS,

KATHLEEN KING. 

